Perhaps you should try some spelling variations:
thanh hoa » thanh pho
thanh hai » thanh phan, thanh san
su sach » so sach, vu sach
cam duc » cam xuc, cao duc, pham duc
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
nang xa » lang xa, nang ma, mang xa
va cam » va cham, va cac, va cao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty ((nang xa) or (nang x)) hoi. hieu va cam duc ban ((thanh hai) OR (thanh hoa)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang xa) OR (nang x)) hoi. hieu va cam duc ban ((thanh hai) OR (thanh hoa)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((nang xa) or (nang x)) hoi. hieu va cam duc ban ((thanh hai) OR (thanh hoa)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang xa) or (nang x)) hoi. hieu va cam duc ban ((thanh hai) OR (thanh hoa)) cua tre*.